package com.lagou.edu.factory;

import com.lagou.edu.anno.MyAutowried;
import com.lagou.edu.anno.MyService;
import com.lagou.edu.anno.MyTransactional;
import com.lagou.edu.pojo.Account;
import com.lagou.edu.utils.TransactionManager;
import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;

/**
 * @author 应癫
 * <p>
 * <p>
 * 代理对象工厂：生成代理对象的
 */
@MyService(value = "proxyFactory")
public class ProxyFactory {

    @MyAutowried
    private TransactionManager transactionManager;

    // public void setTransactionManager(TransactionManager transactionManager) {
    //     this.transactionManager = transactionManager;
    // }

    /*private ProxyFactory(){

    }

    private static ProxyFactory proxyFactory = new ProxyFactory();

    public static ProxyFactory getInstance() {
        return proxyFactory;
    }*/


    /**
     * Jdk动态代理
     *
     * @param obj 委托对象
     * @return 代理对象
     */
    public Object getJdkProxy(Object obj) {

        // 获取代理对象
        return Proxy.newProxyInstance(obj.getClass().getClassLoader(), obj.getClass().getInterfaces(),
                new InvocationHandler() {
                    @Override
                    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                        Object result = null;
                        if (obj.getClass().isAnnotationPresent(MyTransactional.class)) {
                            try {
                                // 开启事务(关闭事务的自动提交)
                                transactionManager.beginTransaction();
                                result = method.invoke(obj, args);
                                // 提交事务
                                transactionManager.commit();
                            } catch (Exception e) {
                                e.printStackTrace();
                                // 回滚事务
                                transactionManager.rollback();
                                // 抛出异常便于上层servlet捕获
                                throw e;
                            }
                        } else {
                            result = method.invoke(obj, args);
                        }
                        return result;
                    }
                });

    }


    /**
     * 使用cglib动态代理生成代理对象
     *
     * @param obj 委托对象
     * @return
     */
    public Object getCglibProxy(Object obj) {
        return Enhancer.create(obj.getClass(), new MethodInterceptor() {
            @Override
            public Object intercept(Object o, Method method, Object[] objects, MethodProxy methodProxy) throws Throwable {
                Object result = null;
                if (obj.getClass().isAnnotationPresent(MyTransactional.class)) {
                    try {
                        // 开启事务(关闭事务的自动提交)
                        transactionManager.beginTransaction();
                        result = method.invoke(obj, objects);
                        // 提交事务
                        transactionManager.commit();
                    } catch (Exception e) {
                        e.printStackTrace();
                        // 回滚事务
                        transactionManager.rollback();
                        // 抛出异常便于上层servlet捕获
                        throw e;
                    }
                } else {
                    result = method.invoke(obj, objects);
                }
                return result;
            }
        });
    }

    public Object getProxy(Object obj) {
        Object proxy = null;
        Class<?>[] interfaces = obj.getClass().getInterfaces();
        if (interfaces.length > 0) {
            proxy = getJdkProxy(obj);
        } else {
            proxy = getCglibProxy(obj);
        }
        return proxy;
    }
}
